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Dinosaurs Timeline

Dinosaurs are a large yet very specific group of creatures. To qualify, an animal has to satisfy a number of criteria 0 It must have lived during the Mesozoic era (see page 10). 0 It must be a reptile, although not all reptiles are dinosaurs. For example, lizards are reptiles, but they are not dinosaurs. 0 Its legs must be located below its body, giving it an erect stance, as opposed to sticking out from the sides, like those of a crocodile. 0 It must have lived on land, not in the air like...

One of the rarest dinosaurs ever discovered, Xiaosaurus is something of a mystery. We know so little about it that palaeontologists can't even say which family it's from. We do know, however, that Xiaosaurus is a small, two-legged, or bipedal, dinosaur. We also know it's a plant-eater and from what we have seen, palaeontologists believe it might live in family groups. Family Not known Period Mid Jurassic Where found China Height 0.5 metre 0-7 feet) Si - ill' - *i Kl B I iggia Si - ill' - *i Kl...

Dinosaurs have been discovered on every continent on earth, although some areas have a larger concentration of finds than others. This may indicate either the amount of time spent excavating the fossil beds (areas with a high concentration of fossils) or the number of dinosaurs that lived in a particular area.

Besides its very long neck, another contributing factor to the extreme height of Brachiosaurus is the fact that its front legs are considerably longer than its back ones. This gives Brachiosaurus an unusual upright stance and a marked advantage. As any giraffe knows, the youngest, juiciest shoots are often found at the top of a tree, and, if you're taller than anyone else, you're going to be the one who eats them. Penod Late Jurassic Herght 16 metres (53 feet) length 30 metres (99 4 Special...

If you're spotting dinosaurs in Argentina be sure to look out for this placid plant eater - and, at this size, it shouldn't be too difficult to find. Plant eaters continue to get bigger as the reign of the dinosaurs goes on. Food is plentiful, and its size enables this larger dinosaur to reach taller vegetation. There's also a measure of security Riojasaurus is just too big for most carnivores to take on.

Although Allosaurus has relatively short arms, they are bigger and stronger than those of Tyrannosaurus rex, who you'll meet later. These arms are also equipped with sharp claws, which mean that Allosaurus can cling onto its prey while attacking its victim with savage bites.

The following is just a selection of famous dinosaur sites from around the globe 0 Dinosaur National Monument, Utah, USA 0 Dinosaur Provincial Park, Alberta, Canada 0 North Rhine-Westphalia, Germany 0 Cretaceous Valley, Patagonia, Argentina Winton, Queensland, Australia Looking for fossils can be long, hard and frustrating work. Many people find nothing, not even a two-a-penny sea creature, much less a dinosaur. Even the professionals return empty-handed some of the time. The idea, however,...

If Trachodon is not quite an obsolete name, it is certainly of a dubious nature. When dinosaur hunter Joseph Leidy found a couple of teeth in the 1850s, he thought they were from a completely new species of dinosaur - one that he named Trachodon, which means 'rough tooth'. However, in time, there were mutterings that all might not be well with Trachodon. The discovery of Hadrosaurus was enough to convince some people that the two species were in fact one and the same. Other discoveries...

Like many plant eaters, Hadrosaurus lives much easier to spot any danger lurking in herds. Group living is a simple defence close by if many animals are on the against attack from predators, and it's lookout rather than just one. Family Hadrosauridae Period Late Cretaceous Where found USA For ages, palaeontologists wondered whether dinosaurs such as Hadrosaurus spent most of their time in water. They have paddle-like hands and tails well suited to propelling themselves through the water. Their...

Like its cousin, Diplodocus, Seismosaurus has a long neck. In addition to allowing it to graze over a large area without moving, it also allows the dinosaur to nose around places its bulky body prevents it from going, such as in between trees. Seismosaurus has peg-like teeth, like Diplodocus. These are ideal for stripping vegetation from trees or low-lying shrubs but they're not so good for chewing up food. As a result, Seismosaurus swallows the leaves and stems more or less whole. i IBB....

Mamenchisaurus looks a lot like Diplodocus, especially with its long, downward-pointing neck and whippy tail. It is only when you get really close that the differences become apparent, namely the head and teeth. However, we would recommend that you take our word for it and don't venture too H0Wt S LmeMamenchiliZard Meaning of name iv Family Euhelopodidae Period Late Cretaceous

Plateosaurus is one of the earliest plant-eating dinosaurs and is a forerunner - though not a direct ancestor - of huge auropods such as Brachiosaurus. Like the sauropods of later times, Plateosaurus has thick, sturdy legs and a solid body with a long neck and tail. It also lives in herds like its distant sauropod cousins. Since this dinosaur can be spotted right across northern Europe, some palaeontologists believe that Plateosaurus spends its time moving from one place to another looking for...

This odd-looking dinosaur with a parrot-like head may have been the victim of one of the worst miscarriages of justice when it was given a name that means 'egg thief'. Oviraptor's name seems to fit it has a sharp beak and powerful jaws - the right tools needed for breaking eggs open. Further proof seemed to come from fossil remains, which show an Oviraptor crouched over some eggs, evidently in the process of stealing them. Oviraptor was caught bang to rights. Or was it

Corythosaurus is a herd dweller and moves in large groups in a constant search for food. Living in herds offers a degree of protection from predators, which is why so many plant-eaters live in herds. The best place to spot Corythosaurus is near swamps or shorelines because their limbs make moving around this kind of environment relatively easy, and more difficult for predators.

The Jurassic world is certainly a dangerous place to be. Another relative of that dangerous Allosaurus family is the Ceratosaurus - a big, sharp-toothed meat-eater that it is wise to stay well clear of. Ceratosaurus is a typical predator of the Jurassic period. It's big, walks on two powerful legs and has two smaller yet comparatively strong arms with four fingers on each. As a relative of Allosaurus, it may even hunt in packs, an idea that might recently have been proved by the discovery of a...

The most obvious feature of Diplodocus is its extremely long neck and tail. Its neck is about 8 metres (26 feet) long, but at the end of it is a tiny head measuring less than 1 metre (3.3 feet). The tail is just as impressive as the neck and makes an effective whip-like weapon for repelling predators. How to say it d'-PLO-do-KUS Meaning of name Double beam Family Diplodocidae Period Late Jurassic Where found USA Not all long-necked dinosaurs eat leaves from the treetops, and Diplodocus is a...

One of the great debates in the dinosaur world is whether Tyrannosaurus rex is the ferocious predator we always imagined it to be or a sneaky scavenger looking for dead animals to eat. People who believe it is a scavenger point out that tyrannosaurs probably aren't fast enough to catch most dinosaurs. The idea that Tyrannosaurus is a hunter comes from its strong skull bones and sturdy build - exactly what the dinosaur needs to attack other animals. Family Tyrannosaur period Late Cretaceous...

Sauropods are the giants of the dinosaur age. The biggest animals to have walked on land, the sauropods peaked during the Jurassic period. By the late Cretaceous period, they had disappeared from North America, apart from Alamosaurus, who can be found in Texas, Utah and New Mexico. Some palaeontologists believe that these dinosaurs wandered up from South America, where more sauropods may still be found. .1 la-moh-SORE-us How to say rt aMa., ,,,.d Meaning of name Alamo tord Family Titanosauridae...

If you spot Eoraptor there's no point in going any further back in time, because you're at the very start of the dinosaur age Eoraptor is a small, speedy carnivore, with a light build and odd, leaf-shaped teeth. Don't get too close, however, as these teeth have a jagged edge and are very sharp. This dinosaur may only be the size of a pet dog, but it's a lot less friendly.

Dromaeosaurus has the same type of sickle-shaped claws as Deinonychus and Velociraptor, but is smaller. However, Dromaeosaurus does have relatively long and sharp teeth, so if the feet don't get you, the mouth will. Heiqht 0.5 metre 1.5 feet Weight 15 kilograms vpj w SpeciaT eatures Deadly claws

Palaeontologists consider Bagaceratops to be far more primitive than the ceratopids - even though it came later than many of them. Like the ceratopids, Bagaceratops has a relatively stocky build and short legs. However, along with its horn, its crest is nowhere near as large as those of Styracosaurus sty-RAC-o-SORE-us nor is Bagaceratops itself anywhere near as big. Its closest relative is probably Protoceratops pro-toe-KAIR-ah-tops , which is about twice the size of its smaller cousin. With...

Archaeopteryx was the first feathered dinosaur to be found anywhere. Originally, palaeontologists suggested it could be a major link between dinosaurs and birds, but now some think that Archaeopteryx is a bit of a dead end in avian evolution. It has feathers and light bones like birds do, but it also has a flat breastbone and a long, bony tail, which birds don't have. However, Archaeopteryx is some kind of link between feathered and non-feathered creatures and, as such, is a highly prized...

One unusual feature of Iguanodon is its thumb spike - a horny digit on each hand where you might expect the thumb to be. Palaeontologists are still divided over the function of this spike. Some claim it is for defence and can be used to stab an attacking predator. Other scientists are less sure about its effectiveness as a weapon. Maybe it is used for pulling down branches or digging up plants Iguanodontidae Penod Early cretaceous 5 metres ,6.5 feet g lt l gt 10 metres 33 feet' r ji k I Ml r ji...

When Giganotosaurus was first spotted in Argentina, it started a big debate - is this dinosaur the biggest meat-eater ever Many palaeontologists believe that Giganotosaurus is the largest of all the dinosaur carnivores - even larger than Tyrannosaurus rex. From sightings made so far, it certainly seems to be longer and taller than its more famous rival. However, like Carcharodontosaurus, it also seems to be more lightly built than Tyrannosaurus rex, so the argument continues about who is the...

This dinosaur might look a bit odd, but you wouldn't want to say that to its face - this late Cretaceous predator is even longer than Giganotosaurus. The most striking feature of Spinosaurus is the huge sail on its back. This isn't for any kind of defensive purpose - a meat eater like this has little to fear - instead, it is used to regulate the dinosaur's temperature. Blood is pumped around the sail, where it is either heated in the sun or cooled in the shade this, in turn, controls the...

One of the most famous dinosaurs you'll ever see, this big bruiser of a plant-eater is one of the most common Cretaceous dinosaurs. Triceratops is famous for the three sharp horns on its head, which give it its name. Partly for display but mainly for defence, these three prongs are equally effective in scaring off carnivores and male love rivals as they are attracting females. The formidable horns, particularly the pair of metre-long upper horns, are more than sharp enough to kill anything in...

Stegosaurus is the largest member of the stegosaur family - a wide-ranging group of large plant-eating dinosaurs found around the world. The most impressive features of Stegosaurus are undoubtedly the two rows of plates running down its back. When these were first spotted, palaeontologists presumed they were for defence we now know this isn't the case. Firstly, the plates are too weak to hold off another dinosaur. Secondly, they don't really protect the most vulnerable parts of the dinosaur,...

So, if Oviraptor isn't an egg thief, what does it eat It eats both meat and plants, which is unusual for a dinosaur. It might well be tempted to eat the odd egg, too, if one comes its way. Maybe the name isn't so wrong after all. Another of the thick-skulled dinosaurs, yet Pachycephalosaurus is nowhere near as tough as it looks.

Cretaceous-period Australia was attached to Antarctica, so the climate there was very different to that of the present day. For the most part, the weather was cold and the days were dark. Leaellynasaura is adapted for those conditions - it has large eyes, which help it to see in gloomy light, for example. The discovery of Leaellynasaura reopened one of the oldest dinosaur debates - are they warm-blooded or cold-blooded Present-day cold-blooded reptiles aren't well adapted to living in cold...

If group living is the norm, then these dinosaurs' crests become all the more important. Palaeontologists believe that they may be used to generate noise however, the shape is equally important. Each species has a different-shaped crest, which is a great visual pointer for where the rest of a particular dinosaur herd happens to be - very handy if you're on the move most of the time. Mow to say it LAM-be-oh-soRc Meaning of name Lambed lizard Family Hadrosauridae Penod Late Cretaceous Where found...

When Archaeopteryx remains were first unearthed, the dinosaur was thought to be a Compsognathus. However, palaeontologists soon realized that this is one of the most important dinosaur discoveries ever made. Family Coelundea Period Late Jurassic Where found Germany Heiaht 0.3 metre 1 foot iength 0.5 metre 0-6 feet Weight 500 grams 08 ounces

This top-ranking predator is one of the most common and has a great range. Allosaurus can be found in locations as far apart as North America, Australia and Tanzania, which means that plant eaters right across the Jurassic world have plenty to worry about. Allosaurus is at the very top of the Jurassic food chain. For 10 million years this will be the biggest carnivore on the planet. It is more than capable of tackling most plant eaters, even up to the medium-sized sauropods. However, some...

Not many dinosaurs begin with the letter Z, so Zephyrosaurus is something of a collector's item. Keep your eyes peeled for this one if you're spotting in the United States. Early Cretaceous Where found USA Height 1 metre 3 feet Length 2 metres 6 fee We ght Not known Food Plants Special features Agile IBB. iBm sai n Jin iinr ii ji IBB. iBm sai n Jin iinr ii ji Since Zephyrosaurus is a small and agile dinosaur it is really skilled at zipping around. When you have no armour plating or defensive...

This is the last and possibly the most famous of the ankylosaurids. Ankylosaurus is big, wide, heavy and covered in bony plates. This is one well protected dinosaur, and most predators have to think twice before trying to tackle it. The body of Ankylosaurus is all about defence, being covered in thick plates of bone fused into the dinosaur's skin. This forms a hard, shell-like structure over the creature it even has bony plates over its eyes. Not only that, but its body is covered in rows of...

Deinonychus derives its name from the huge claw on its second toe. The claw is so large that it would get in the way when Deinonychus walks, unless the dinosaur can keep it pulled back retracted from the ground, like a cocked trigger on a gun. The claw is undoubtedly a fearsome weapon, but no one has got close enough to see precisely how it's used. Palaeontologists once presumed that Deinonychus would slash through the flesh of its unfortunate victim, but palaeontologists now believe the claw...

Kentrosaurus has a striking combination of spikes and plates that run down its back and tail. The upper part of the back has a double row of plates the lower portion and tail a double row of spikes. The spikes appear to be defensive but the plates are a little less easy to explain. Perhaps Kentrosaurus can make them change colour as part of a courtship display. Or maybe they are for regulating the dinosaur s temperature a series of blood vessels near the surface could help cool or heat the...